The present invention relates to a method and a corresponding arrangement for the customization of a footwear, i.e. for adapting the footwear to the specific morphology of the particular user. More specifically, the present invention relates to a method and arrangement for the customization of a footwear, more particularly a sports footwear, comprising an element made of thermoplastic material.
According to prior art, footwear are manufactured in a variety of sizes that are different in length and width. However, each footwear size has standard length and width and not all the users with the same foot size have foot with the same morphology. It results that, while the size is correct, often the footwear does not fit the particular morphology of the user's foot. This drawback is particularly felt in the field of sports footwear, as the user's feet—during sports practice—are subject to considerable efforts.
Moreover, in the field of sports footwear, the conformity of the footwear to the specific morphology of the particular user remarkably affects not only the user's comfort, but also his/her performances.
The aforesaid drawback turns to be particularly limiting in the case where the sports footwear comprises a substantially rigid element.
Reference can be made, by way of example, to ski boots, which usually comprise a substantially soft inner element or inner liner and a substantially rigid outer element or outer shell. In the case of ski boots, not only does the conformity of the footwear to the morphology of the foot of the particular user increases the user's comfort, but it also improves the maneuverability of the ski, since even minimal movements of the user's foot are transmitted effectively to the ski boot and from this to the ski.
Similar improvements to the user's comfort as well as to his/her performances can be obtained for other similar sports footwear comprising a substantially rigid outer shell, such as, for instance, roller skates or ice skates.
It is also apparent that making custom-made footwear, while allowing efficient customization on one hand, would on the other hand involve high manufacturing costs and, consequently, very high, non-competitive market prices. In the past methods and arrangements for the customization of sports footwear were developed starting from a standard, non-customized article, which could therefore be manufactured on a large scale.
Still referring to the (non-limiting) example of ski boots, the known methods and arrangements can be classified into three categories:                methods and arrangements providing for modifying the shape and size of the inner liner for adapting it to the morphology of the user's foot;        methods and arrangements providing for introducing an insert with variable shape and size between the user's foot and the inner liner or between the inner liner and the outer shell; and        methods and arrangements providing for modifying the shape and size of the outer shell for adapting it to the morphology of the user's foot.        
Referring to the last category, the known methods and arrangements provide for making the outer shell of the ski boot from a thermoplastic material, whereby its shape and size can be modified if it is heated to a temperature higher than a predetermined threshold. The known methods and arrangements further provide that, once the outer shell has been heated, a pressure is applied to the shell from the outside, so that the shell is pressed against the user's foot.
In this respect, there can be cited U.S. Pat. No. 3,613,271, in which pressure is applied manually to the heated shell, or also U.S. Pat. No. 3,848,286, in which the ski boot is held under vacuum, whereby it is the atmospheric pressure of the surrounding environment that presses the shell against the user's foot. Such methods and arrangements can be effective in cases where the user's foot is, at least locally, small with respect to the ski boot shell. In such cases, the compression exerted by the shell causes the shell to adapt itself to the morphology of the user's foot, thus eliminating gaps between the user's foot and the ski boot, which gaps might lead to poor comfort and worse sports performances.
However, the known methods and arrangements are not applicable to cases in which the user's foot is, at least locally, large with respect to the shell of the ski boot. Such is the case, for instance, with users having very protruding malleoli or having a very wide plantar surface, especially in the metatarsal region. It is apparent that this foot conformation may involve a troublesome, if not painful, pressure against the inner wall of the ski boot, which significantly limits the user's comfort, especially during sports practice.
However, in these cases, the known methods and arrangements, which provide for pressing the shell of the boot against the user's foot, can only further worsen the situation.
The main object of the present invention is to overcome this drawback of prior art, by providing an alternative method and arrangement for the customization of a footwear, more particularly of a sports footwear. More in detail, the main object of the present invention is to provide a method and arrangement for the customization of a sports footwear, more particularly a sports footwear, which can be effectively applied to those cases in which the user's foot is—at least locally—large with respect to the footwear of the correct size.
Another object of the present invention is to provide a method and an arrangement for the customization of a footwear, more particularly a sports footwear, that allow to customize the footwear while the user's foot is inserted in the footwear.
These and other objects are achieved with the method and the arrangement as claimed in the appended claims.